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Discussion Starter · #1 ·
With both AO48s and a set of R888s, I've run 26F/28R hot with pretty good success. Even temps, rollover almost to base of triangles. At higher pressures tires feel dead to me, fronts won't turn the car well.
I've seen many recomendations (including manufacturers) that recommend higher pressures than street, way up in the 30s.
I'm putting a new set of R888s on Road Atlanta tomorrow, and plan to aim again for 26/28 hot.
Any discussion/experience/criticism? Directions to threads?
 

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I pretty much run similar pressures - 25 F , 28 R Hot.
I used to run really low pressures - 22 and 25 hot because I thought that I felt better grip rolling on the sidewalls, but this was a waste. When my tires were done the centers still had tread....so I'd stick with what you're doing.
Some guys that like more of a looser feel do run higher pressures though.
 

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There's been a lot of discussion about R888 tire pressures... but it seems that it's very much related to load (car weight). Lighter cars should run lower pressures... I've had better results with pressures similar to plastique999's
 

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i like a stiffer sidewall.... i run about 31-33 hot range, pretty close to 26-28 cold. i like the feedback, the times i have run lower hot pressures, the car felt a little soggy and sidewalls rolling over too much. i have a stiffer set up now - and so i might have a different opinion once i get the nitrons on the track.

28-30 'ish range is about as low as i go hot. some of that is preference too.
 

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Discussion Starter · #6 ·
So the higher recommended pressures are based on 3000lb+ cars?
I've sat in an HPDE class where it was recommended to raise pressures above street. Seemed curious to me as track use was going to heat them up and raise pressure even more. Is there a rational for this, on any weight car?
 

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So the higher recommended pressures are based on 3000lb+ cars?
I've sat in an HPDE class where it was recommended to raise pressures above street. Seemed curious to me as track use was going to heat them up and raise pressure even more. Is there a rational for this, on any weight car?
This might be a little simplistic... but consider that the tire engineers optimized the compound, construction, and tread profile for a certain size/area contact patch... since the area of the contact patch is a function of weight divided by tire pressure, it makes sense that lighter cars should run proportionally lower tire pressures to get the same contact patch area.
 

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It's too bad they don't make the RE070 in the correct sizes for the car, as then you could have your cake and eat it too...super low pressures for a larger contact patch, and super stiff sidewall for great turn-in/feel.
 

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My feeling with this is I would go with what you have used in the past that felt good to you, and adjust accordingly to your pyrometer readings.
do have a probe type pyrometer? if not, purchasing one is a good investment.
tire PSI can/will vary per track, driving style, car set up, track temperature, etc........, so you really should learn to have the confidence in your own intuition, and rely on the right tools to dial in your car.
if you dont know how to work a pyrometer and adjust according to the readings it gives, PM me and i will be glad to help you.
 

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Spend $150 on a good pyrometer. Adjust your pressures and camber until your temperature readings are appropriate. This is a much better method than listening to a bunch of yahoos on this site. Remember that track surface and outside temperatures can have a significant impact on required tire pressure. Even if you are running the exact same camber and pressure as another member (that tested his camber/pressure to be appropriate), the track surface/outside temperature variables could make the other member's recommendations false for you.
 

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here is a link to the same one i bought for more than this guy is asking for his.


Race Ads | For Sale: Longacre Tire Pyrometer

I used to use one w/o the memory feature, and just write stuff down , but it was cumbersome to have the pencil/paper, and pyrometer.

I really like this one, and wouldnt go back to the non-memory one now that i have used this one.

Disclaimer;
I have no idea what condition this is in, or any ties to the seller, this is where i bought mine, and its been perfect.

if the OP doesnt buy this thing, someone else who needs one should .
 

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Discussion Starter · #12 ·
After one run, even temps, not a lot of rolloverwith hot temps 29/31.4
 

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Discussion Starter · #13 ·
So this is my result from the weekend. I went well towards my former comfort zone of 26/28, ending up at 27/29. Pretty hot day, about 92, so I'd let air out all day long. Temperatures were within a couple of degrees F across the thread, in the mid 140s LR, 130s RR, and 120 both fronts. Obviously I was not working them hard. Rollover:

Font Vehicle Car Number Triangle
 
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